Mixing, stirring and dispersing device



MarCh 29, 1966 VON GUSTORF ETAL 3,243,164

MIXING, STIRRING AND DISPERSING DEVICE Filed May 25, 1964 2 Sheets-Sheet 1 INVENTORS 5, von Gustorf 4- BY H. ,Bornemann ATT'YS March 29, 1966 VQN GUSTQRF ETAL 3,243,164

MIXING, STIRRING AND DISPERSING' DEVICE 2 Sheets-Sheet 2 Filed May 25, 1964 INVENTORS 5., volv Gustorf qt- BY H.Bo'rnemcznn ATTYS.

United States Patent MIXING, STIRRING AND DISPERSING DEVICE Ernst Koerner von Gustorf and Heinrich Bornemann,

Mulheim an der Ruhr, Germany, assignors to Studiengesellschaft Kohle m.b.H., Mulheim an der Ruhr, Germany Filed May 25, 1964, Ser. No. 369,839

Claims priority, application Germany, May 27, 1963,

4 Claims. (Cl. 259-8) This invention relates to a novel mixing, stirring and dispersing device in which a stirring member carried by a rotatable shaft and telescopically received in an immovable sleeve admixes media introduced through openings in the sleeve opposing similar-openings in the stirring member whereby complete and thorough stirring and dispersing of the media is accomplished.

:..Conventional mixing and dispersing devices are known in which a sleeve ortube is firmly fixed at one end to a housing of a; conventional drive means, such as an electric motor, and the opposite ,end of the tube has a plurality of; inwardly directed mixing vanes or agitating implements. A shaft of the drive means is telescopically received in the sleeve and carries outwardly directed rotary mixing vanes or implements generally opposing the sleeve vanes. Bearings at each end of the shaft mount the same for rotation, and in order to obtain maximum mixing, the vanes of the shaft are numerous, relatively large and the speed of the rotation of the shaft is extremely high. These conditions elfect high loading of the bearings and result in the rapid and costly wear thereof.

The load on the bearings has been mitigated to some extent in prior art mixing devices by maintaining the diameter of the shaft vane or vanes greater than the length thereof. However, this construction gives rise to certain difficulties in the use of such prior art mixing devices, particularly in laboratory applications.

For example, the diameter of the shaft vanes, which are generally disposed in a ring about the lower end of the shaft, determines the size of orifices or neck openings in vessels, such as beakers, etc. through which the mixing device is introduced into the vessel. The majority of such devices found in commercial use cannot be introduced into such standard size laboratory glassware. In many cases, for example, when working with an air-sensitive compound or in the quantitative reaction of gases with/ or in liquids, gas-tight introduction of the sleeve, shaft and stirring member into a vessel forming a portion of the reaction system is necessary yet cannot be effected with conventional devices, particularly those employing conventional corks, rubber stoppers, or similar perforated and pervious stoppers. In addition, no devices of the type described are known which effectively preclude the entrance of the dispersant or media being agitated into the bearings, particularly under relatively long periods of stirring at both high and low pressures. In known devices the introduction of the media into the bearings is increased to major proportions because of the necessity of the location of the bearings immediate the area of the stirring member, due again, to the size of the vanes, the diameters thereof and the high peripheral speed of the shaft. Finely-divided solid matter and organic solvents act as abrasives and cause bearing wear, especially at high temperatures. Therefore, such prior art devices are limited for use with less aggressive media, as for example, aqueous media.

In each known case of the mixing and dispersing devices, thorough cleansing of the device is practically impossible especially if slight damage, wear or misalign- 'ment of the bearings occurs. "In many cases the downice time for cleaning the device is greater than the time in which the device is used.

Another disadvantage of a majority of conventional devices of the type described is that they are suitable only for limited operation from a time standpoint due to considerable friction losses at high speeds of operation causing excessive heating to an extent that faultless performance is at best questionable.

In keeping with the above it is an object of the present invention to provide an agitating, mixing, stirring and dispersing device in which each of the aforementioned disadvantages in known conventional prior art stirring devices are obviated or mitigated.

In accordance with the present invention an agitating device or stirring member is positioned at a free end of a rotatable driving shaft, the stirring member being provided with a plurality of relieved portions or openings and being of a generally cylindrical configuration thereby effecting a relatively small diameter both at the end portion of the device adapted for introduction into vessels of the type mentioned and also being relatively small in diameter in comparison to known prior art stirring devices in the area at which bearings mounting the shaft are located.

A further object of this invention is to provide a novel dispersing device of the type described in which one or a plurality of sleeves which are either adjustable or interchangeable are mounted in surrounding relationship relative to the shaft and stirring member, and are provided with a plurality of relieved portions or openings opposing the openings in the stirring member.

Still another object of this invention is to provide a novel dispersing device of the type described and including pressure-tight and vacuum-tight packing of the bearings thereof in a housing whereby the dispersing device can be driven under conditions of high vacuum and/or high pressure heretofore unprovided for by prior art conventional stirring devices.

A further object of this invention is to provide the openings in both the sleeve and stirring member running parallel to, perpendicular to, or at a predetermined angle to the axis of the rotating shaft, and mounting the stirring member in a removable manner upon the shaft whereupon selected slot or opening sizes and dispositions can be selected at random dependent upon the material to be mixed by the device.

A further object of this invention is to provide a novel dispersing device of the character described in which the stationary sleeve and the distance thereof from the stirring member carried by the shaft can be varied by replacing or substituting shafts or stirring members of diverse lengths and diameters, thereby effecting or providing a device in which high-frequency cutting and impact effects along with an outstanding mixing and dispersing effect is provided by centrifugal action between the openings in the sleeve and stirring member and the gap or space between these members.

A further object of this invention is to provide a novel dispersing device of the character described, and in addition, to provide a novel bearing housing surrounded by a cooling jacket through which is passed a cooling liquid for a cooling gas so that the bearings rotatably mounting the shaft can be maintained at a constant desired temperature during prolonged operation of the device, and in addition, the sleeve is also cooled to a certain extent by conduction so that the latter operates as a reflux condenser against any steam rising from the system being agitated.

A further object of this invention is to provide a novel dispersing device of the character described in which each 'of the components thereof which are subjected to mechanical wear may be readily changed in a simple manner and in a relatively short period of time.

The invention will now be described, by way of example, with reference to the accompanying drawings, in which:

FIGURE 1 is a fragmentary longitudinal sectional view of the dispersing device constructed in accordance with this invention, and illustrates a drive shaft rotatably mounted by bearings which are, in turn, surrounded by a cooling chamber and including a stirring member having openings opposing openings in a sleeve telescopically surrounding the shaft.

FIGURE 2 is a transverse sectional view taken along line 22 of FIGURE 1, and illustrates members for introducing coolant into and withdrawing coolant from the cooling chamber of FIGURE 1.

FIGURE 3 is a transverse sectional view taken along line 33 of FIGURE 1, and illustrates a conduit or pipe for introducing a liquid or gaseous media into an annular gap between the sleeve and shaft of the device.

FIGURE 4 is a transverse sectional view taken along line 4--4 of FIGURE 1, and illustrates opposed axially extending openings in the stirring member and sleeve and a generally annular gap therebetween.

FIGURE 5 is a transverse sectional view taken along line 55 of FIGURE 1, and similarly illustrates opposed openings at a lower portion of the stirring member and the sleeve.

A novel mixing, stirring and dispersing device constructed in accordance with this invention is best illustrated in FIGURE 1 of the drawings to which attention is now directed, and includes a bearing housing 3 fastened by means of a bolt 2 and an intermediate member 3a to a conventional driving member or driving means 1, as for example, an electric motor. A driving shaft 5 having an upper end portion thereof secured to the output shaft of the driving member 1 by means of a radially directed screw 4 depends generally vertically downwardly through a packing gland 6. The packing gland 6 consists of a plurality of packing rings 5a which are secured in intimate engagement by means of a screw plug 7.

A liquid lubricant, for example silicon fluid, is led to the gland 6 and the several packing rings 5a thereof through a channel 8 which is hermetically sealed against a reservoir 9 by means of a removable screw 10. A plurality of drill holes (unnumbered) in the screw plug 7 supply oil from the reservoir 9 to the packing rings of the gland 6 in a manner clearly illustrated in FIGURE 1 of the drawings. The reservoir 9 is filled and emptied through an orifice 11a into which is threadably secured a removable screw 11. The orifice 11a also renders the screw 4 joining the driving shaft 5 to the driving means 1 accessible from the exterior of the device for purposes of removing, inspecting and if necessary, repairing the same.

A lowermost end portion of the shaft 5 beneath the gland 6 and the individual packing rings is inserted into a relatively larger diameter shaft 12. The shaft 12 is illustrated as being of a one-piece integral construction of which a lower end is relatively narrow as compared to an upper end thereof, but it is within the scope of this invention to construct the shaft 12 of one or more sections. A screw 13 secures the shaft 12 to the shaft 5 in a conventional manner.

A plurality of ball bearings 14 surround an upper end portion 12a of the shaft 12 remote from a lower end portion thereof and permit relative rotation of the shaft 12 by the driving connection thereof with the shaft 5 and the driving means 1. A hollow generally cylindrical stirring member 15 is fastened by a screw 17 to a lowermost end portion 12b of the shaft 12. The stirring member 15 is provided with a plurality of relieved portions, openings or slots 16 which are illustrated as being identically circumferentially spaced about the stirring member 15 and in general parallelism with the axis of the shaft 12.

However, it is to be understood that the number, arrangement, disposition, configuration and size of the openings or slots 16 can be varied depending upon conditions of operation, such as the dispersant or media being mixed, the relative pressure and temperature conditions of the particular mixing operation, etc.

The housing 3 is surrounded by a cooling jacket 13 which is supplied by fluid coolant (gas or liquid) through and from pipes or conduits 19 from respective coolant reservoirs (not shown) of a conventional construction.

A sleeve or tube 21 surrounding the shaft 12 is secured by a threaded portion 20 to a lower end portion 3b of the housing 3. A lowermost end portion 21a of the sleeve 21 opposing the stirring member 16 is provided with a plurality of relieved areas, slots or openings 22 which are equally circumferentially spaced about the sleeve and are generally parallel to the axis thereof. The slots 22 correspond in number, disposition, size, etc. to the slots 16 in the stirring member 15 and, again, depending upon the particular conditions of use the slots 22 can be identical in shape and size to the slots 16 or can differ therefrom in shape, size, number and disposition. For example, in the preferred embodiment of the invention illustrated in FIGURE 1 the slots 16 and 22 are arranged in parallel relationship but either the slots 16 or the slots 22 can be arranged at an angle relative to the axis of the shaft 12 and the sleeve 21.

A conduit or pipe 23 is placed in fiuid communication by means of a radial port 23a with an annular gap or chamber 25 between the interior of the sleeve 21 and the exterior of the shaft 12. The conduit 23 is adapted for connection to a source of gaseous media for gassing or aerating the substance or media which is agitated either under pressurized or vacuum conditions.

An annular gasket 24 of elastomeric material, such as rubber or plastic, maintains a gas-tight joint between the housing 3 and the portion 20 of the sleeve 21.

While the preferred form of the invention has been described in connection with preferred components thereof, variations and substitutions thereof may be made within the scope and purpose of this disclosure. For example, the threaded connection between the portion 20 of the sleeve 21 and the housing 3 can be replaced by a magnetic coupling and the driving means 1 can as well be an oil pressure turbine instead of an electrically driven motor.

From the foregoing it is believed apparent that the disclosed stirring, mixing and dispersing device meets the requirements of those skilled in the art, particularly laboratory technicians, biologists, chemists, etc. and others in a varied range of technical activities requiring precise, eflicient and effective dispersing devices.

The disclosed dispersing device is especially suitable for carrying out chemical reactions in liquid systems with or between undissolved solid materials, as well as for carrying out gaseous reactions in said systems.

The device constructed in accordance with this invention is particularly useful for and is advantageous in such fields of endeavor as compounding metallo-organ'ic compounds, ag regates and co-catalysts under absolute anaerobic conditions. The device is also useful for forming sensitive contacts and surface-active materials, quantitative precipitation reactions under anaerobic conditions, as Well as the carrying out of catalytic reactions with undissolved catalysts and gas reactions with hetergeneous liquid systems, as for example, catalytic hydrogenation with hydrogen-Raney-nickel in the absence of vibratory appliances. Oxidation with oxygen, even in unhoinogeneous systems, carbonylizing and halogenating reactions, and dehydrohalogenating in unhomogeneous systems can be accomplished with relative ease and efiiciency by the novel stirring, mixing and dispersing device of this invention.

Further possibilities of use arise in the degassing of high boiling point viscous liquids prior to molecular distillation, surface renewal in sublimation, continuous extraction and sundry other chemical, metallurgical physio-mechanical operations of a technical nature requiring admixing, and dispersing of liquid or gaseous media.

While the novel dispersing device has been described and illustrated to including specific components and arrangements thereof, it is to be understood that variations thereof will be apparent to those skilled in the art after reviewing this disclosure, and such variations are considered to fall within the scope of the invention as defined by the appended claims.

What is claimed is:

1. A stirring device comprising a bearing housing having a bearing chamber therein,

an elongated stirring shaft projecting from said chamber in said housing through an opening, bearing means in said chamber, said shaft having its inner end rotatably mounted in and surrounded by said bearings means, said bearing means in the said chamber being the sole support of said shaft, said shaft having a stirring member at the outer end thereof,

drive means associated with said bearing housing in engagement with the said inner end of said shaft for rotation of said shaft,

an elongated sleeve projecting from said housing over said opening, which sleeve closely surrounds and freely encloses the projecting portion of said elongated stirring shaft and the said stirring member,

said sleeve having formed therein adjacent its outer end a plurality of transverse stirring openings, and

said stirring member having stirring portions operating in proximity to the transverse openings in said sleeve.

2. A stirring device comprising a bearing housing,

bearing means in said housing,

an elongated stirring shaft projecting from said housing having its inner end rotatably mounted in said bearing means,

drive means associated with said bearing housing in engagement with said inner end of said shaft for rotation of said shaft,

a sleeve projecting from said housing, which sleeve surrounds and encloses the projecting portion of said elongated stirring shaft,

said sleeve having formed therein adjacent its outer end a plurality of transverse stirring openings,

a stirring member mounted on the outer end of said stirring shaft, said stirring member having stirring portions operating in proximity to the transverse openings in said sleeve,

said sleeve being releasably connected to said housing for easy substitution of another sleeve housing varying in size and/ or in mixing characteristics, and

said stirring member being releasably removable from said shaft through the outer end of said sleeve.

3. A stirring device comprising a bearing housing,

bearing means in said housing,

an elongated stirring shaft projecting from said housing having its inner end rotatably mo n ed in id bearing means,

drive means associated with said bearing housing in engagement with the said inner end of said shaft for rotation of said shaft,

a sleeve projecting from said housing, which sleeve surrounds andencloses the projecting portion of said elongated stirring shaft,

said sleeve having formed therein adjacent its outer end a plurality of transverse stirring openings, a stirring member mounted on the outer end of said stirring shaft, said stirring member having stirring portions operating in proximity to the transverse openings in said sleeve,

said sleeve being slightly spaced from said shaft to provide an annular chamber between said stirring shaft and said sleeve, said chamber being axially positioned between said bearings and the outer end of said sleeve,

said annular chamber at its inner end being connected to a fluid inlet port and having fluid under pressure admit-ted to said annular chamber through said port, and

said annular chamber at its lower end being in fluid communication with said transverse stirring openmgs,

whereby fluid will flow downwardly through said chamber and will prevent the material being stirred from moving inwardly along said shaft into the said bearings in said housing.

4. A stirring device comprising a bearing housing,

bearing means in said housing,

an elongated stirring shaft projecting from said housing having its inner end rotatably mounted in said bearing means, drive means associated with said bearing housing in engagement with the said inner end of said shaft for rotation of said shaft,

a sleeve projecting from said housing, which sleeve surrounds and encloses the projecting portion of said elongated stirring shaft,

said sleeve having formed therein adjacent its outer end a plurality of transverse stirring openings,

a stirring member mounted on the outer end of said stirring shaft, said stirring member having stirring portions operating in proximity to the transverse openings in said sleeve,

means carried by said shaft for attachment to said drive means, and

reservoir means for accommodating a lubricant adjacent said attachment means.

References Cited by the Examiner UNITED STATES PATENTS 2,793,166 5/ 1957 Hatch 2598 FOREIGN PATENTS 934,793 8/1963 Great Britain. 485,397 10/1953 Italy.

82,655 9/ 1956 Netherlands. 86,310 10/ 1955 Norway.

WALTER A. SCHEEL, Primary Examiner.

CHARLES WILLMUTH, Examiner.

ROBERT W. JENKINS, Assistant Examiner. 

1. A STIRRING DEVICE COMPRISING A BEARING HOUSING HAVING A BEARING CHAMBER THEREIN, AN ELONGATED STIRRING SHAFT PROJECTING FROM SAID CHAMBER IN SAID HOUSING THROUGH AN OPENING, BEARING MEANS IN SAID CHAMBER, SAID SHAFT HAVING ITS INNER END ROTATABLY MOUNTED IN AND SURROUNDED BY SAID BEARINGS MEANS, SAID BEARING MEANS IN THE SAID CHAMBER BEING THE SOLE SUPPORT OF SAID SHAFT, SAID SHAFT HAVING A STIRRING MEMBER AT THE OUTER END THEREOF, DRIVE MEANS ASSOCIATED WITH SAID BEARING HOUSING IN ENGAGEMENT WITH THE SAID INNER END OF SAID SHAFT FOR ROTATION OF SAID SHAFT, AN ELONGATED SLEEVE PROJECTING FROM SAID HOUSING OVER AND OPENING, WHICH SLEEVE CLOSELY SURROUNDS AND FREELY ENCLOSES THE PROJECTING POSITION OF SAID ELONGATED STIRRING SHAFT AND THE SAID STIRRING MEMBER, SAID SLEEVE HAVING FORMED THEREIN ADJACENT ITS OUTER END A PLURALITY OF TRANSVERSE STIRRING OPENINGS, AND SAID STIRRING MEMBER HAVING STIRRING PORTIONS OPERATING IN PROXIMITY TO THE TRANSVERSE OPENINGS IN SAID SLEEVE. 